Electric control system



Jan. 13, 1931. D. R. PUTT ELIECTRIC CONTROL SYSTEM Original Filed 001;. 4, 1927 IN VEN TOR.

ATTORNEY Patented Jan. 13, 1931 UNITED STATES,

PATENT OFFICE- DONALD E. PUTT, OF HUNTINGDON, PENNSYLVANIA, ASSIGNOB OF ONE-HALF '10 ALVA 3. SEE, OF NEW YORK, N. Y.

ELECTRIC conraor. sYs'rEir Application filed October 4, 1927, Serial No. 228,988. Renewed April 1, 1980 alternating current.

In carrying out my invention I make use of thewell known phenomena of the magnetic field which surrounds an electricalcon ductor through which a current is passed and utilize this efiect to control movements of a vehicle by causing this field to induce a current at certain times in another circuit which prime mover of connects to and controls the the vehicle.

Accordingly I lace one or more electrical conductors at pre etermined points along the line of travel of the vehicle and pass a current therethrough having a predetermined and known characteristic. I also place another conductor, such as a coil, in proximity to the first conductor so as to have current induced therein from the first inductor and provide means, such as a magnetic shield, for interrupting this inductive efiect in accordance with movements of the vehicles to be controlled. The indirectly energized conductor is connected through suitable means to the driving force of the vehicle in such manner to control the same.

My invention may well be adapted to the control of. elevator cars either automatic, semi-automatic or manually operable, either operating sin ly orin banks either to signal the car, actuzilly regulate the movements of the car or merely indicate the movements thereof. It is understood that in the following description I shall use the term control to include indicating, signalling or regulating when used in connection with car and that the word car shall include an elevator car or any other car operating singly or as a unit of a group of such cars.

Thus by placing conductors in an elevator shaft, an inductor or pickup coil u on a car and shielding or interrupting the rst mentioned conductors throughout except at the landings, the car may be automatically 1ev at the will of the operator to eliminate the automatic feature, in that respect the actual leveling would in either case be automatic.

It is obvious that the conductors may be shielded only at the floor levels and the interruption of current flow in the pickup coil be utilized to control the car.

A more detailed description will be given in connection with the drawings in which:

Fig. 1 is a diagrammatic representation of one embodiment of my invention;

Fig. 2 is a detail of a portion of the mag netic shield showing an adjustable plate thereon and the method of continuing the shield around all but one conductor, and

Fig. 3 is a section through the conduit at one of the openings.

In the embodiments of my invention illustrated in the drawings by way of illustration I have shown an instance where the'conductors are shielded and the shielding is continuous except at the locations where the car is to be leveled and I have also shown a system in which twoconductors carrying two currents of different characteristics are utilized to bring the car to complete rest.

I have also shown a car that is not fully automatic i. e. it is necessary for the operator to first close the pickup coil circuit after which theactual controlling is automatic and the term automatic hereafter used refers to this feature. It is obvious that this feature may be omitted to make the system full automatic or modified to make it semi-automatic.

A car is indicated by numeral 1 traveling in a shaft 2 between guide rails 3, the floor levels being indicated at 4 and 4a.

The car is operated through the usual starting lever 5 having a contact segment 5a thereon of the control mechanism mounted in the car and which is connected in customary manner through wires 6 to the sourte of power 7, which ma be either direct or alternating currents, ancl direction switches 8 and 8a which determine the direction of rotation of the main driving motor 9 and consequently the direction of travel of car 1. The speed of rotation of the driving motor 9 may be varied by means of an armature resistance 10 and a shunting circuit 11 therefor, and a field resistance 12 also provided with a shunting current 13 having a switch 14 therein normally closed and adapted to be opened by an electromagnet 15. All of the foregoing is the standard elevator structure and need not be described in further detail here.

In the shaft 2 I place a pair of conductors 16 and 17 within a metallic conduit 18 having magnetic properties and extending up two sides of the shaft and across the top, the two conductors being connected to and supplied with current from two alternators 20 and 20a which may be mounted upon a common shaft and driven from a common motor 21 connected to and energized from the common source of power 7. Alternators 20 and 20a are designed to generate current at different frequencies, alternator 20 at 135' cycles per second and alternator 20a at 50 .cycles per second for example) for reasons whichwill later appear. The conduit 18 has an opening 18a therein at each side of the shaft at each floor level and also a similar opening slightly below the floor level upon one side of the shaft and slightly above the floor level upon the other side of the shaft.

At the openings adjacent each floor level an auxiliary shield 19 which may be a section of iron tubing conveniently supported from the conduit, surrounds conductor 16 in order to prevent any magnetic flux set up thereby from transversing coils 25 and 25a. At the openings immediately above and below the floor levels a similar shield is placed around conductor 17. These shields extend slightly above and below the openings in the conduitto insure the confinement of the lines of flux set up by the current'flowing in the conductors. Cover plates 22 are provided over each of the openings, the plates having an opening 23 in the center thereof somewhat smaller than those in the conduit and slots 24 at each end whereby the plates may be ad justably secured to the conduit in such man- .ner that the effect thereof is to vary the position of the openings inthe conduit within limits of the slots.

Upon the bottom of the car at each side adjacent the conductors 16 and 17 I mount'a pickup coil 25 and 25a their axes being'at right angles to conductors 16 and 17 one end of each coil being connected together as at 26 and connected th ough wire 27 to the blocking condenser 2 a to the common or filament terminal of a vacuum tube amplifier comprising two vacuum tubes 28 and 28a. The other end of each pickup coil is connected through a pair of switch contacts 30 and. 30a mounted upon the control mechanism within the car and then through conductor wire 34 then through signed to prevent currents of a fre uency vacuum tube 28 is closed through contacts .30 or 30a, acoil 25 or 2511 res ectively, conductors 26, 27, condenser 27a, ament of the tube 28, grid 31 and conductor 3012. Tube 18 will thus be connected to receive any impulses of current picked up by either coil 25 or 25a.

The filaments of the amplifier tubes 28 and 28a are connected through a potentiometer 33 across the common source of current 7 and the plate current for the tubes may also conveniently be taken from the common source .through suitable choke coils. The pulsating output current resulting from the alternating current impressed upon the grids of the amplifying tubes in the illustrated embodiment of my invention, although other embodiments may readily be realized, may take one of two paths in accordance with the frequency of this output current. One path leads from the plate of the last tube 28a through wire 34 and blocking condenser 34a to the energizing coil of a solenoid 35 through wire 50 to filament of amplifier tubes thus completing the circuit. Solenoid 35 controls a switch 36 in a shorting circuit for short circuiting the lockout coil 37a of a lockout relay 37, the armature 38 of which is pivoted intermediate its ends and is biased in the usual manner against the action of pull in coil 38a and in effect is the lever of a single pole double throw switch normally biased to close a portion of a circuit comprising wires 39 and 40 leading from the control switch in the car to the energizing coil of electromagnet '15 of the field. resistance circuit previously described. In its alternate POSltiOIl armature 38 closes anfother circuit through wire 41 to the pull in coil 42 of a second lockout relay 43 having an armature 44E controlling with contact 43a the circuit to the direction switches 8 and 8a, the armature being biased against the action of coil 42 by a lockout coil 45 around which is a short circuiting circuit adapted to be closed by the, armature of an electromagnet 47 which is energized from the output current taking the second path which is from the am lifier tubes through ter 48 which is degenerated by alternator 20 i. e. 135 cyc es per second from passing through and to permit current of a frequency of 50 cycles, that generated by alternator 20a, to pass through whereby electromagnet 47 will only be enerfirst close the pickup coil circuit at a desired point before the system. will automatically level'the car, the operation is as follows: The operator desiring to start the car upward 'will swing lever 5 to the right whereby con-.

tact segment 5a will first bridge the upper two switch contacts and close the circuit to the direction switch 8. Upon further move ment segment 5a will bridge the upper three contacts which will energize coil 15, open switch 14, and insert resistance 12 in the field circuit thereby increasing the speed of the car to full speed. If thereafter the operator desires to stop at floor 4, for instance, he then swings auxiliary lever 31 to the right and closes contacts 29 energizing lockout coil 37a and pull in coil 38a of relay 37 also ,energizing lockout coil 45 of relay 43 by connecting one side of these coils to the side of the service line marked through wires 37b, 47 b, 370, contact 29 and conductor 6 to the side of the line. The other side of these coils is connected to the side of the line marked by conductor 470. Lever31 will also close contacts 30 thus closing the pickup coil or grid circuit of tube 28 asheretofore described. As

the car approaches the opening in the conduit 18 below the level of floor 4 the magnetic flux emanating therefrom will cut the pickup coil 25 and induce a current therein due to conductor 16, carrying current of 135 cycles conductor 16 being unshielded at this point, conductor 17 being shielded by auxiliary shield 19. This induced current is impressed upon the grids of the vacuum tube amplifier which causes the plate current output to pulsate at a like frequenc This output current at 135 cycles passes t rough wire 34 is blocked by the filter 48 and passesthrough condenser 34a,- through coil 35, and back through wire 50 to filament of tubes 28-and 28a thus completing the circuit. Coil 35 closes switch 36 which shortcircuits lockout coil 37a of lockout relay 37 and permits pull i-n coil 38a to i once of conductor 17 which is unshielded at this point whereas conductor 16 is shielded. This induced current is passed through the amplifier and comes out on wire 34; passes through filter 48 due to its low impedance to current at this frequency and along wire 3 49 to blocking condenser 49a to coil 47 thereby energizing this coil and back through wire 50 to filament of tubes 28 and 28a thus completing the circuit. Coil 47 closes its associated contacts and short circuits lockout coil 45 of lockout relay 43 thereby permitting pull in coil 42 previously energized to function and actuate armature 44 to open contact 43a thus opening the current of the actuatin coil of direction switch 8 which opens an stops the driving motor and consequently the car. The exact points of application of the two steps in leveling the car may be varied by adjusting cover plates 22 over the openings in the conduit. It is apparent that more steps may be employed if desired.

It is obvious that should the operator decide to stop after passing the slow down opening but before reaching the upper or stop opening in the conduit at the floor level it would be too late to level thecar at that floor level and the mechanism would not function since pull in coil 42 would not have been previously'energized in readiness for the stopping action and the operator would eitherhave to bring the car to a stop by complete manual control or go by the'floor and automatically level on the down movement for which similar mechanism has been provided to be operative when lever 5 is moved toward the left.

It can readily be seen the principles of the system disclosed and described can be A applied by anyone skilled in the art to any car operating in a bank of cars as well as to a single car and'to either a full automatic the spirit and scope of the. invention as defined in the appended claims. I claim: A

actuate the armature 38 to open'its upper con-\ 1. A control system for automatically con- I tact which opens the circuit to electromagnet Armature 38 also closes its lower contact and approaches the openin in the conduit,

'ad]acent the floor level coi 25 has induced when actuated and thereby closes the circuit to pull in coil 42 of lockout relay '43 in preparation for the next action.

As the car travels upward at reduced speed said means to said driving .said motor 1n accordance with the current trolling a motor driven elevator car, comprising an electrical conductor connected to a source of current and disposed 1n lnductive relation to the car at predetermined points along the shaft, means carried by the/car adapted to have a current induced therein as the car with said means approaches said conductorat said points, and connections from motor to control induced in said means.

2. A control system for automatically controlling a motor driven elevator car, com

be applied to train controls or I prising an electrical conductor connected to a source of current and disposed in inductive relation to the car at predetermined points along the shaft, means carried by the car adapted to have a current induced therein as the car with said means approaches said conductor at said points, and connections from said means to said driving motor selectively operable at will to control said motor in accordance with the current induced .in said means.

3. A control system for automatically controlling a motor driven elevator car, comprising a plurality of electrical conductors connected to different" sources of current having different characteristics and disposed in inductive relation to the car at predetermined points along the shaft, means carried by the car adapted to have a current induced therein as said car and said means approach said conductor at said points, and connections from said means to said driving motor to control said motor in accordance with the character of said current induced in said means.

4. A control system'for automatically controlling a motor driven elevator car com prising a plurality of electrical conductors connected to different sources of current having different characteristics and disposed in inductive relation to the car at predetermined points along the shaft, means carried by the car adapted to have a current induced therein as said car and said means approach said conductor at said points, and connections from said means to said driving motor selectively operable at will to control said motor in accordance with the character of said current induced in said means.

5. A control system for automatically controlling an elevator car comprising an intermittently magnetically shielded electrical conductor connected to a source of current and disposed along the/line of movement of said car, in accordance with movements of said car adapted to'have a current induced there-,.

in as said car and said means approach unshielded portions of said conductors, and connections from said means to the car driving means to control said latter means in accordance with the current induced in said movable means. a

6. A control system for automatically controlling an elevator car, "comprising an intermittently magnetically shielded electrical conductor connected to a source of currentand disposed along the line of motion of said car, an inductor carried by said car adapted to have a current induced therein as said car and said means approach the unshielded portions of said conductor,and connections from said means to the car driving means, selectively operable at will to control said latter means in accordance with the current induced in said movable means.

7. In a control system for elevator cars adapted to automatically stop a car at any desired point in its line of movement, the combination with an electrical conductor extending along the line of motion, and a shield of magnetic material having openings therein at predetermined points along said shaft, of a pickup coil adapted to have current induced therein the said openings in the shield and connections from said coil to the car driving means to control said latter means.

8. In a control system for elevator cars to automatically stop a car at any desired point in its movement, the combination with an electrical conductor extending vertically along the line of motion, a conduit of magnetic material surrounding said conductor having openings therein at predetermined points in said line of motion and covers for said openings also having apertures therein, said covers being adjustably secured to said conduit over the openings therein, of a pickup coil adapted to have current induced therein as the car approaches said openings in the conduit and connections from said coil to the car driving means to control said latter means.

9. In a control system for elevator cars adapted to automatically stop a car at any desired point in its line of movement, the combination with" electrical conductors extending along the line of motion carrying currents of known and different characteristics, a conduit of magnetic material surrounding said conductors having openings therein, of a pickup coil adapted to have current induced therein as the car approaches said openings in the conduit and connections from said coilto the car driving means to control the said latter means.

10. In -a control system for elevator cars adapted to control a car at any desired point in its line of movement, the combination with electrical conductors extending along the line of motion and carrying currents of known and difi'erent frequencies, a conduit of magnetic material surrounding said conductors having openings therein at said points, and a magnetic shield surrounding all but one of said conductors in said conduit at each of said openings, of a pickup coil on the car adapted to have current induced therein as the car approaches said openings in the conduit and connections from said coil to the and different frequencies, a conduit of magnetic material surrounding said conductors having openings therein adjacent said points in the line of motion, and a magnetic shield surrounding all but one of said conductors in said conduit at each of said openings, of a pickup coil on the car adapted to have current induced therein as the car approaches said openings in the conduit and connections from said coil to the car driving means to control the same, said connections including current amplifiers and filter circuits said latter circuits being adapted to separate currents of difl'erent frequencies induced in said coil and transmit them along difi'erent paths.

12. A control system for controlling an elevator car comprising two electrical conducting members disposed in inductive relation to each other, a shielding member for interrupting the inductive effect of one conductor upon the other, one of said members being movable with respect to the others in accordance with movements of said car and connections from oneof said conductors to the car operating means to control the same.

13. A control system for controlling an elevator car comprising two electrical conducting members disposed in inductive relation to each other, one of said conductors being connected to a source of current, a-

rent therein at predetermined points and a shielding member for interrupting the inductive effect of said means at redetermined points, one of said members eing movable with respect to the others in accordance with movements of said car and connections from said inductor to the operatin means of said car to control the same where y said car may automatically be controlled.

In witness whereof, I hereunto subscribe my'signature.- I I V i DONALD REPUTT. 

